retire now unused IMSG_CONTROLFD

listener: handle IMSG_CTL_LOG_VERBOSE adjust the logging level and forward it to every client process so they can do so too.

move control to the main process We may want to be able to run multiple listener process eventually, so the first step is to drop IMSG_CONTROLFD and keep the ctl stuff in the main process.

don't install kamirepl it's possibly a really useful tool to debug 9p servers, as it allows to manually craft messages, but it's just not there and I'd like to tag a 0.1 "soonish".

more tweaks for 9p.7

- [regress-extra] fixed test that changes atime and mtime together.

annotate hex values for 9p message types it's a bit easier to debug hexdumps now

use consistently Ar for request params; add paragraph for write

document wstat

add a note about the `size' field in stat

shrink stat table listing

9pclib: fix qid serialization twstat was serializing the qid in the wrong order. While here, add a comment before the qid definition too.

ftp: truncate the file in woc_file The idea behind woc_file is to create or open a file, but it's always used for writing fresh new content, so it's actually an error that it opens a file for writing without truncating it too. It means that if we write less content than what the file already has, we kepp garbage at the end. This adds an extra argument in send_fid (that is actually used only from woc_file now) so that we can pass KOTRUNC for do_open.

fix memory leak in walk_path error path found by clang' static-analyzer

- [regress-extra] added testing for changing atime and mtime using wstat.